"Learning CSS" is a pretty broad topic. Have you checked out http://cssguidelin.es http://cssguidelin.es? It's pretty high level. For some fun stuff you could a

"Learning CSS" is a pretty broad topic. Have you checked out http://cssguidelin.es http://cssguidelin.es? It's pretty high level. For some fun stuff you could also check out flexboxpatterns.com (I'm the author).